1. Field of the Invention
The present invention relates generally to therapeutic compounds for treatment of tumors. More specifically, the invention relates to a method for preparing a bio platinum compound for treating cancerous and non cancerous tumors, as well as preventing the spread (metastasis) of cancer cells in humans and animals.
2. Discussion of the Prior Art
Platinum based drugs are generally coordination complexes with desirable placement in square planar sites. However, success of Platinum based drug ranges between an upper concentration level approaching the toxicity limit where there is a high probability of success, and a lower concentration level where it falls below the minimum required for effective treatment.
Two Platinum complex agents that are widely used in clinical oncology practice are Cisplatin and Carboplatin. Cisplatin is known to cause severe renal tubular damage, reduced glomerular filtration and requires concurrent saline hydration and mannitol diuresis to eliminate any lethal or other potential damage to the kidney. Peripheral neurotoxicity is the most dose limiting factor associated with Cisplatin. Carboplatin on the other hand is known to cause severe nausea and vomiting. Although Carboplatin is relatively free from peripheral neurotoxicity, hematological toxicity where thrombocytopenia, more than leukopenia, becomes a dose limiting factor in anti-tumor treatment.
The existing platinum based anti tumor drugs are generally intravenous injectables, which are administered once in 21 days in combination with chemotherapy. When such platinum drugs are injected intravenously it results in instantaneous rise of the drug concentration level in the body. For such intravenous drugs to be of optimum utility the dosage administered has to be high which subjects the toxicity level to increase. To prevent the toxicity level from rising to the highest limit if a lower dosage is administered, the therapeutic effect of the drug is minimal. Injection leads to quick or instantaneous therapeutic effect, which will be necessary during epidemics but it is coupled with high risk of toxicity.
Moreover, the therapeutic effect of the existing platinum based drugs being intravenous injectables becomes minimal within 4-12 hours of the administration. Currently, there are very few platinum based anti-tumor drugs, which provide optimum therapeutic effect with lower toxicity level but these are injectable drugs and not ingestible. Hence it was essential to invent a therapeutically effective ingestible bio platinum, which would be non toxic or show a minimal level of toxicity.
Orally administrable platinum complexes for anti tumor treatment have been discussed in WO/1999/033782, which does not form prior art in respect of the present invention, as the new process for obtaining the novel bio platinum is completely devoid of any chemical treatment of Platinum metal and also vary in its characteristics and physical properties.